Denoising is a crucial step for hyperspectral image (HSI) applications. Though witnessing the great power of deep learning, existing HSI denoising methods suffer from limitations in capturing the non-local self-similarity. Transformers have shown potential in capturing long-range dependencies, but few attempts have been made with specifically designed Transformer to model the spatial and spectral correlation in HSIs. In this paper, we address these issues by proposing a spectral enhanced rectangle Transformer, driving it to explore the non-local spatial similarity and global spectral low-rank property of HSIs. For the former, we exploit the rectangle self-attention horizontally and vertically to capture the non-local similarity in the spatial domain. For the latter, we design a spectral enhancement module that is capable of extracting global underlying low-rank property of spatial-spectral cubes to suppress noise, while enabling the interactions among non-overlapping spatial rectangles. Extensive experiments have been conducted on both synthetic noisy HSIs and real noisy HSIs, showing the effectiveness of our proposed method in terms of both objective metric and subjective visual quality. The code is available at https://github.com/MyuLi/SERT.
翻译:去噪是高光谱图像(HSI)应用的关键步骤。尽管深度学习显示了巨大的力量,但现有的HSI去噪方法在捕捉非局部自相似性方面存在局限。Transformer已经显示出在捕捉长距离依赖性方面的潜力,但很少有尝试特别设计的Transformer来模拟HSI中的空间和光谱相关性。在本文中,我们通过提出一种光谱增强矩形Transformer来解决这些问题,引导它探索HSI中的非局部空间相似性和全局光谱低秩特性。对于前者,我们利用矩形自注意力在水平和垂直方向捕捉空间域中的非局部相似性。对于后者,我们设计了一个光谱增强模块,该模块能够提取空间-光谱立方体的全局基础低秩特性以抑制噪声,同时实现非重叠空间矩形之间的相互作用。已在合成噪声HSI和真实噪声HSI上进行了大量实验,显示了我们提出的方法在客观指标和主观视觉质量方面的有效性。代码可在https://github.com/MyuLi/SERT上获取。